Bulletin of the Korean Chemical Society最新文献

This study introduces a novel and versatile method for synthesizing honeycomb-structured silicon carbide (SiC). The innovative approach utilizes a sucrose solution as the carbon source and nonporous silica spheres, which serve both as silicon precursors and templates, allowing for precise control over pore sizes. Notably, the process is characterized by its cost-effectiveness, eco-friendliness, and the utilization of milder conditions attributed to magnesiothermic reduction. The tunable pore sizes achieved through adjustments in the size of silica particles offer a versatile platform for customizing SiC materials to meet specific application requirements. Beyond its customizable nature, the method reduces the environmental footprint of SiC synthesis by utilizing eco-friendly materials. Its combined attributes of accessibility, sustainability, and performance optimization underscore its potential for driving advancements in SiC-based applications across various industrial and scientific domains.

Polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs) have been important monitoring targets in the atmosphere due to their deleterious biological effects. Pine needles have been used to monitor atmospheric pollutants. An analytical method was developed to measure 21 PAHs, 14 alkyl PAHs, 7 PCBs, and 23 OCPs in pine needles using ultrasonically assisted extraction and gas chromatography-tandem mass spectrometry (GC–MS/MS). The ranges of the lower limits of detection of PAHs, PCBs, and OCPs were 0.01–0.05, 0.02–0.06, and 0.01–0.07 μg/kg, respectively. The feasibility of the proposed method was validated by analyzing dust standard reference materials of the samples, which gave satisfactory results with a precision of 0.83%–7.80% (PAHs), 0.93%–4.78% (PCBs), and 0.73%–4.71% (OCPs), and an accuracy of 89.2%–102% (PAHs), 94.6%–109% (PCBs), and 99.4%–102% (OCPs). The PAHs, PCBs, and OCPS were determined from real pine needle samples using the developed method.

Conducting polymers (CPs) possess the intrinsic attractive properties of conventional polymers, coupled with unique electronic characteristics reminiscent of metals or semiconductors. Nanostructured CPs have recently gained significant interest for their distinct advantages over bulk counterparts. They demonstrate potential applications in energy storage devices, sensors, and catalysts, attributed to their large surface areas and shortened charge transport paths. A crucial structural aspect in this context includes introducing porous morphologies into CPs, and enhancing their functionality through interconnected channels. In this review, various synthetic methods of nanostructured CPs are introduced, emphasizing two-dimensional (2D) configurations. The primary objective is to achieve high-performance devices with highly organized stacking of conjugated backbones. Particular attention is placed on integrating 2D structures and porous morphologies into CPs through ice-assisted methods and interfacial synthesis. The review also highlights successful applications of porous 2D CPs in practical devices and explores insights into future developments in the porous CPs field.

Transition metal dichalcogenides (TMDs) are promising 2D materials which are attracting significant interest because of their distinctive physicochemical properties. The possibility of being exfoliated and dispersed in liquid solutions offers a viable pathway to scalable production. This personal account focuses on recent advancements in 2D TMD inks produced by liquid-phase exfoliation (LPE) methods and intercalation-based electrochemical exfoliation. In particular, different LPE production strategies, like ultrasonication LPE, high-shear mixing exfoliation, and microfluidization, are introduced alongside a broad range of liquid media employed to provide functionalized TMD inks. The main advantage of TMD inks is its scalability, for practical applications in printed optoelectronics, energy storage, and conversion. Furthermore, the chemical functionalization of TMD inks can solve the poor electrical conductivity attributed to edge defects inherent in TMD inks. Finally, the ultimate orientations for future applications of chemically functionalized TMD devices are forecasted, with a specific focus on wearable and flexible printed electronics.

Identification of cancer from normal tissues is important for early diagnosis of cancer. Combined detection of multiple tumor markers is important for accurate diagnosis. It is urgent to develop fluorescent probes that are responsive to multiple cancer characterizations for selective cancer imaging. Herein, we designed a novel near-infrared (NIR) fluorescent probe (IRAPA) using a hemi-cyanine skeleton as fluorophore and 3-acrylamidopropanoic ester as recognizing unit that is responsive to both oxidative and reductive molecules. IRAPA has faint fluorescence emission as the intramolecular charge transfer (ICT) process is blocked. H₂O₂, glutathione (GSH) and cysteine (Cys) can individually induce the hydrolysis of ester bond and give fluorescent NIR IROH. IRAPA shows low cytotoxicity and produces strong fluorescence specifically in cancer cells/tissues. While the normal cells/tissues showed very weak fluorescence. Moreover, IRAPA shows higher differences between cancer and normal cells compared to probes that only response to biothiols or ROS.

Three co-substituted quaternary and quinary Zintl phases belonging to the Ba_1-xSr_xZn_2-yCu_ySb₂ (x = 0, 0.09; 0.24 ≤ y ≤ 0.42) system were prepared by the molten Pb metal-flux method. Co-substitution using the cationic Sr and anionic Cu for Ba and Zn was initially applied to lower the thermal conductivities and to improve the electric conductivities of these title compounds simultaneously. The homogeneities of single-phase products were verified by powder x-ray diffraction analysis, and the BaCu₂S₂-type orthorhombic crystal structures with the Ba/Sr and the Zn/Cu mixed-sites were refined by single crystal x-ray diffraction analysis. Structural selectivity for the observed BaCu₂S₂-type phase was rationalized by the radius ratio of cationic and anionic elements, where r₊/r₋ > 1. DFT calculations using the three structural models revealed that the Sr and Cu substitutions can increase the structural stability and the hole carrier concentration. A series of temperature-dependent electrical transport property measurements for BaZn_1.76Cu_0.24Sb₂ and Ba_0.91Sr_0.09Zn_1.70Cu_0.30Sb₂ successfully proved that the co-substitution using Sr and Cu enhanced electrical conductivities, but reduced the Seebeck coefficients resulting in the slight change in power factor.

Unnatural β-amino acids play pivotal roles in organic synthesis, drug development, and peptide chemistry. Highlighting their significance, the study by Jungwoo Hong, Wonchul Lee, and Hee-Seung Lee presents an optimized, scalable method for producing enantiopure five-membered cyclic trans-β-amino acid building blocks. More details are available in the article by Jungwoo Hong, Wonchul Lee, Hee-Seung Lee

Although organic photovoltaics (OPVs) have evolved over the last two decades, the discovery of new materials and optimization of numerous considerations for high-performance devices remain challenging. To reduce these laborious processes and expedite the advancement of OPVs, we constructed machine learning (ML) models that predict photovoltaic parameters. We designed a unique descriptor that divides the molecular structure into smaller units and translates them into a concise matrix. This allows the ML model to easily track structural units and understand which units are important for predicting target performance, enabling the ML model to prioritize crucial units. Therefore, without requiring additional data from measurements or calculations, the ML models can extract chemical properties from molecular structural information and accurately predict the photovoltaic parameters. The ML models that predict the photovoltaic parameters, including the open-circuit voltage, short-circuit current density, fill factor, and power conversion efficiency, all show remarkably superior prediction performance, with Pearson correlation coefficients exceeding 0.68. Consequently, in this article, we propose a highly precise and reliable predictive OPV-ML platform that can robustly screen for unnecessary experiments and accelerate OPV development.

This work analyzes the crystal structural properties and photoluminescence properties of six Eu²⁺-activated thiogallates: CaGa₂S₄:Eu²⁺, SrGa₂S₄:Eu²⁺, EuGa₂S₄, BaGa₂S₄:Eu²⁺, Sr₂Ga₂S₅:Eu²⁺, and Eu₂Ga₂S₅. Photoluminescence parameters such as the absorption energy (E_abs), emission energy (E_em), zero-phonon line energy (E₀), Stokes shift (ΔS), and red shift (D) are discussed. This work is the first report on the photoluminescence parameters of these six Eu²⁺-activated thiogallates and therefore provides important information about these materials.

The synthesis and functionalization of privileged nitrogen heterocycles has emerged as a central topic in drug discovery and material science. In this context, the tandem C–H functionalization and intramolecular annulation has received prodigious attention, as it is able to expedite the construction of heteroaromatic frameworks beyond conventional C–H functionalization. In general, significant effort has been made to develop the [3 + 2] dipolar cycloaddition of azomethine imines with π-unsaturated compounds. Moreover, the [3 + 3], [4 + 3], [3 + 2 + 2], and [5 + 3] cycloaddition reactions of azomethine imines with various dipolarophiles have been demonstrated. To date, however, the combination of catalytic C–H functionalization and intramolecular cyclization using azomethine imines as both directing groups and dipolar units has been less explored. This review focuses on recent progress toward the catalytic tandem C–H functionalization and dipolar cycloaddition of azomethines imines with a range of coupling partners.